linux-stable/kernel/sched
Rafael J. Wysocki ee2cc4276b cpufreq: Add special-purpose fast-switching callback for drivers
First off, some cpufreq drivers (eg. intel_pstate) can pass hints
beyond the current target frequency to the hardware and there are no
provisions for doing that in the cpufreq framework.  In particular,
today the driver has to assume that it should not allow the frequency
to fall below the one requested by the governor (or the required
capacity may not be provided) which may not be the case and which may
lead to excessive energy usage in some scenarios.

Second, the hints passed by these drivers to the hardware need not be
in terms of the frequency, so representing the utilization numbers
coming from the scheduler as frequency before passing them to those
drivers is not really useful.

Address the two points above by adding a special-purpose replacement
for the ->fast_switch callback, called ->adjust_perf, allowing the
governor to pass abstract performance level (rather than frequency)
values for the minimum (required) and target (desired) performance
along with the CPU capacity to compare them to.

Also update the schedutil governor to use the new callback instead
of ->fast_switch if present and if the utilization mertics are
frequency-invariant (that is requisite for the direct mapping
between the utilization and the CPU performance levels to be a
reasonable approximation).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-15 19:24:18 +01:00
..
autogroup.c sched/autogroup: Make autogroup_path() always available 2019-06-24 19:23:40 +02:00
autogroup.h
clock.c sched/clock: Use static_branch_likely() with sched_clock_running 2019-11-29 08:10:54 +01:00
completion.c completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() 2020-03-23 18:40:25 +01:00
core.c sched/deadline: Fix priority inheritance with multiple scheduling classes 2020-11-17 13:15:28 +01:00
cpuacct.c sched/cpuacct: Fix charge cpuacct.usage_sys 2020-05-19 20:34:14 +02:00
cpudeadline.c sched/deadline: Implement fallback mechanism for !fit case 2020-06-15 14:10:05 +02:00
cpudeadline.h
cpufreq.c cpufreq: Avoid leaving stale IRQ work items during CPU offline 2019-12-12 17:59:43 +01:00
cpufreq_schedutil.c cpufreq: Add special-purpose fast-switching callback for drivers 2020-12-15 19:24:18 +01:00
cpupri.c sched/rt: cpupri_find: Trigger a full search as fallback 2020-03-20 13:06:20 +01:00
cpupri.h sched/rt: Optimize cpupri_find() on non-heterogenous systems 2020-03-06 12:57:27 +01:00
cputime.c sched/cputime: Improve cputime_adjust() 2020-06-15 14:10:00 +02:00
deadline.c A couple of scheduler fixes: 2020-11-22 13:26:07 -08:00
debug.c sched/debug: Fix memory corruption caused by multiple small reads of flags 2020-11-10 18:38:49 +01:00
fair.c A couple of scheduler fixes: 2020-11-22 13:26:07 -08:00
features.h sched/rt: Disable RT_RUNTIME_SHARE by default 2020-09-25 14:23:24 +02:00
idle.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
isolation.c isolcpus: Affine unbound kernel threads to housekeeping cpus 2020-06-15 14:10:03 +02:00
loadavg.c sched: nohz: stop passing around unused "ticks" parameter. 2020-07-22 10:22:04 +02:00
Makefile kcsan: Improve various small stylistic details 2019-11-20 10:47:23 +01:00
membarrier.c rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ 2020-09-25 14:23:27 +02:00
pelt.c sched: Add a tracepoint to track rq->nr_running 2020-07-08 11:39:02 +02:00
pelt.h sched/pelt: Cleanup PELT divider 2020-06-15 14:10:06 +02:00
psi.c sched,psi: Convert to sched_set_fifo_low() 2020-06-15 14:10:25 +02:00
rt.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
sched-pelt.h sched/fair: Fix "runnable_avg_yN_inv" not used warnings 2019-06-17 12:15:58 +02:00
sched.h sched/features: Fix !CONFIG_JUMP_LABEL case 2020-10-14 19:55:46 +02:00
smp.h sched/headers: Split out open-coded prototypes into kernel/sched/smp.h 2020-05-28 11:03:20 +02:00
stats.c
stats.h psi: Move PF_MEMSTALL out of task->flags 2020-03-20 13:06:19 +01:00
stop_task.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
swait.c sched/swait: Prepare usage in completions 2020-03-21 16:00:23 +01:00
topology.c Scheduler changes for v5.10: 2020-10-12 12:56:01 -07:00
wait.c list: add "list_del_init_careful()" to go with "list_empty_careful()" 2020-08-02 20:39:44 -07:00
wait_bit.c sched/wait: fix ___wait_var_event(exclusive) 2019-12-17 13:32:50 +01:00